The son of Freeman Libby and the first American to down five enemy aircraft during World War I, Frederick Libby never flew a combat mission for the United States Air Service. He became an ace while serving as an observer with 11 Squadron in the Royal Flying Corps. When the war began, Libby was in Canada where he joined the Canadian Overseas Expeditionary Force on 12 February 1915. Upon reaching France, he served as a truck driver but was wounded and returned to England in December 1915. When he recovered, he volunteered for service with the Royal Flying Corps. "I had 10 hours of flying before going into combat," he would later say. As an F.E.2b observer, the Colorado cowboy became the first American ace of the war in the summer of 1916. The following year, Libby completed pilot training and was posted to 43 Squadron on 18 April 1917. After scoring 2 victories, he was re-assigned to 25 Squadron as a D.H.4 pilot in August 1917. At the request of General Billy Mitchell, Libby transferred to the American Air Service on 15 September 1917. Returning to the United States, he participated in the Liberty Loan drive before joining the 22nd Aero as an instructor at Hicks Field in Texas. Unfortunately, Libby was seriously ill by this time and was found to be permanently disabled and medically unfit for further military service.

Temp. 2nd Lt. Frederick Libby, Gen. List, and R.F.C.
For conspicuous gallantry in action. As observer, he, with his pilot, attacked four hostile machines and shot one down. He has previously shot down four enemy machines.